Adjustable indexable drill

ABSTRACT

An adjustable drill has a drill body having a face surface with a directional feature provided therewith. At least one cartridge is mounted adjacent the face surface and selectively slidable along the directional feature to provide adjustment. At least one insert is releasably affixed in an insert pocket provided in the cartridge. In further examples, the adjustable drill may have a central cutting system in combination with the adjustable cartridge type system, wherein the central cutting system may be modular. There may also be provided a modular type of holder arrangement to provide flexibility to adapt the system for various applications.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This U.S. Patent Application is a continuation-in-part (CIP) of U.S.patent application Ser. No. 12/134,766 filed on Jun. 6, 2008 which isincorporated herein by reference in its entirety. This application alsoclaims the benefit of U.S. Provisional Application Ser. No. 60/942,493,filed Jun. 7, 2007 and PCT/US08/66087 filed on Jun. 6, 2008.

TECHNICAL FIELD

The present invention generally relates to an indexable and adjustablesize drill for producing a hole in a work piece.

BACKGROUND

Conventional twist type drills have been used for many years, generallybeing formed of hardened steel. Solid carbide drills provide desiredstrength characteristics for machining, but have various limitations.The development of drilling tools with indexable inserts overcomes someof these limitations. Indexable drills utilize cutting edges on one ormore indexable, replaceable inserts. The inserts may be seated inpockets on the cutting end of a drill body. The pockets may have a shapecorresponding to at least a portion of the shape of the insert. Theinserts may be indexable, meaning that when the cutting edges wear inoperation, the inserts may be removed or loosened from their position onthe drill body, then rotated, or indexed, a pre-determined amount toenable use of additional cutting edges on the insert. At least onecutting geometry is associated with the insert, which may be on two ormore index locations, such as for example an approximately triangleshaped insert having cutting geometry at three positions, anapproximately square or other quadrilateral shaped insert having cuttinggeometry at four positions, or other suitable shapes. Inserts may bemade of a material harder and/or denser than the drill body.

Indexable inserts may be capable of cutting feeds and speeds greaterthan a conventional twist type drill. Inserts may be carbide materialsor similar materials that have a suitable hardness or may be hardened toprovide a cutting edge with a hardness greater than the material beingdrilled. Indexable drills may be of a “one flute effective”, “two fluteeffective” or multi-flute effective design, where one or more insertsare provided, each having one flute effective. Twist type drillsgenerally have two effective flutes.

Although useful for many applications, indexable drills may not be aseffective for smaller holes, for example ¾ inch (about 19 millimeters)or less as the design will typically be one flute effective. Inoperation, a single one flute effective indexable insert may be slowerthan a two flute effective twist drill or a two flute effective spadeinsert drills. Spade type inserts have a front “blade type” drillingpoint and may be of carbide construction or a fine grain tool steel.

As mentioned, indexable drills may utilize one or more replaceableinserts, that are cost effective, particularly as the drill size getslarger or material gets more difficult to drill. An indexable drill mayoperate at a faster rotational speed, cutting greater surface area thana “spade type” drill, allowing a faster feed advancement. Anotheradvantage of the indexable drill over a conventional spade drill, solidcarbide drill, or conventional twist drill, is that the inserts areconsumables. Instead of regrinding the cutting edge, the insert may beindexed to a new cutting edge and then thrown away when all the cuttingedges are worn.

Indexable type drills are generally known in the art as a “roughingtool” because indexable drills may not be self-centering as in othertype drilling products. Problems such as the insert flutes on anindexable not being a mirror of each other, as in spade drills or otherproducts for example, causing non-uniform cutting forces in theoperating drill. In the past, the drill may be held in the desiredcutting path by a machine spindle, and the accuracy may be dependant onthe rigidity of the machine and spindle, and the setup holding the part.For this reason, prior indexable drills may not be effective fordrilling holes having a depth greater than 3 times the diameter. Atdepths greater than 3 times the diameter, the accuracy of prior artindexable drills may be reduced and the forces on the machine andmachine spindle may become greater.

Indexable drills, or rough hole tooling, in the past have been made inrough hole size ranges. As the prior art drills increase in size, thedifference in size from one drill to the next larger size may be about ¼inch (about 6 millimeters) diameter or more. The end-user may havedifficulty boring a hole in a single pass to a size between the priorart drill sizes. Until now, there has been little improvement inproviding close drill tolerance holes in the larger drill sizes of about1¼ inch to 5 inch (32 millimeter to 127 millimeter) and instead separateboring products are used to finish the rough hole.

Further, hole diameters between standard sizes in the past could beaccommodated by special order drills. However, the lead time and expenseof special order items can be high due to their low production volume,non standard size, and special engineering and sales involvement. Theexpense and time in obtaining these special size drills may dissuade theend user from purchasing a special drill and causing additional expenseof added operations.

Also in past indexable drills, during operation, the physical cuttingconditions for indexable insert drills may vary from the outside edge ofthe hole towards the center of the hole diameter, due to the differentlinear velocities of the cutting edges passing over the material. Nearthe center of the diameter, the linear velocity of the cutting edge maybe very low. In prior indexable drills, at the low linear velocity ofthe center, the mechanical cutting action may be like a chisel thatextrudes material. As the distance from the center increases, the linearvelocity of the inserts increase, and the cutting edges may effectivelyshear the material. In the past, the low linear velocity at the centerof the hole can cause a drill failure. To accommodate the low linearvelocity at the center of the hole, drills of the prior art haveattempted to utilize a center-cutting insert having a different shape,or insert material, or a special cutting edge.

Also, as the prior drills increase in size, the drill may be configuredwith larger sized inserts. As the insert size and shape become larger,the insert screw that retains the insert in its pocket may also change.A user having many hole sizes to create must carry a large inventory ofinserts, grades of inserts, and screw sizes. The end user having holesranging as little as 1.5 inches (38 millimeters) from the smallest tothe largest, may have as many as 30 to 45 separate components toinventory.

Drills that are not balanced can cause chatter. Because indexableinserts may not be two flute effective and may not be uniform, priorindexable drills have been difficult to balance. In the past. indexableinserts have been honed or made with flat ground cutting edges toprotect the edges from chatter or movement common in the prior artindexable drills. For this reason, more power was required for pastdrills with the honed or flat ground insert edges used in the prior art.

Indexable drills in the prior art also rely on a volume of coolant toexpel the drilling chips from the hole during drilling. The chipscreated by the cutting action have to move back from the cutting edgesand be expelled from a gullet adjacent the cutting area to keep chipsfrom wedging in the clearance between the drill body and the cutdiameter. Coolant may be pumped through the drill body, exiting on thedrill end and flowing backward through pressure and momentum and pushingthe chips backward up the gullet. The coolant may include a watersoluble oil that may form a mist under heat and pressure of cutting. Thecoolant may be a health hazard to an operator when breathed and has tobe contained thru filtration or other processes to reduce the airborneinhalation by machine operators.

In past indexable drills, the drill failure point may be near the centerinsert area. The center area may pack with chips unable to move back andover drill body structure, and out of the formed hole.

SUMMARY OF THE DISCLOSURE

The present invention relates to an adjustable drill comprising a drillbody having a longitudinal axis, comprising a face surface comprising anaperture extending into the drill body; a directional feature adjacentthe aperture extending toward an edge of the drill body; a longitudinalgullet extending from the face surface along at least a portion of thedrill body; a cartridge adjacent the face surface and selectivelyslidable along the directional feature comprising: a slot along thedirectional feature; and a cutting face comprising an insert pocketpositioned adjacent the edge of the drill body; a fastener through theslot into the aperture releasably affixing the cartridge to the drillbody; and an insert releasably affixed in the insert pocket.

The adjustable drill may further comprise a second face surfacecomprising a second aperture extending into the drill body; a secondcartridge adjacent the second face surface comprising a through hole;and a second cutting face comprising an insert pocket positionedadjacent the axis of the drill body; a fastener through the hole intothe second aperture releasably affixing the cartridge to the drill body;and an insert releasably affixed in the insert pocket.

The adjustable drill may further comprise inserts of differentconfigurations which may provide alternative cutting characteristics inconjunction with the adjustable drill.

In an alternative embodiment, the adjustable drill may further include acentrally positioned drilling insert that allows for increased stabilityduring operation of the drilling system, while still allowingindexability by means of the insert configurations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of an adjustable indexable drillof the present disclosure with portions removed for clarity;

FIG. 2 is a front view of the drill of FIG. 1;

FIG. 3 is a partial view of cartridges and inserts of the drill of FIG.1;

FIG. 4A is a side view of a portion of the drill of FIG. 1;

FIG. 4B is a top view of the portion shown in FIG. 4A;

FIG. 4C is a side view of the drill of FIG. 1;

FIG. 4D is a top view of the drill shown in FIG. 4C;

FIG. 5 is a top view of the drill of FIG. 1;

FIGS. 6A-6D show views of an example of a trigon insert usable inconjunction with the present disclosure;

FIGS. 7A-7D show views of an example of the drill with an alternativeinsert configuration;

FIGS. 8A-8D show views of an example of the drill with an alternativeinsert configuration; and

FIGS. 9A-9D show views of an example of the drill with an alternativeinsert configuration.

FIGS. 10A-10D show views of an alternate embodiment of the inventionhaving a centrally disposed cutting insert in association therewith.

FIG. 11 shows a cross sectional view of an alternate embodiment similarto FIG. 10.

FIG. 12 shows a cross sectional view of an alternate embodiment similarto FIG. 10.

FIGS. 13A-13D show partial views of an embodiment having a centrallydisposed cutting insert with the smallest and largest cutting diametersare shown.

FIG. 14 shows an embodiment of a modular holder that may be used withthe invention.

FIG. 15 shows an exploded view of an embodiment of the modular holdershown in FIG. 14.

FIG. 16 shows an exploded view of the connections between components ofa modular holder embodiment.

FIG. 17 shows an exploded view of the connections between components ofa modular holder embodiment.

FIG. 18 shows a cross sectional view showing an embodiment of theconnection between components of a modular holder arrangement.

FIGS. 19-22 show alternative embodiments of holder arrangements that maybe used in the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The invention relates to an adjustable indexable drill, with an examplepresently disclosed, wherein the drill may utilize one or more insertcartridges and indexable cutting inserts. In this example, the indexableinserts drill alleviates many of the deficiencies of indexable drillspreviously described, and provides increased performance efficiency,reduced cost of operation, and elimination of unnecessary operations.The indexable insert drill also reduces the coolant necessary for properoperation, thereby reducing hazards to operators related to possibleinhalation of such coolant materials. As will also be described, theindexable inserts drill provides for smooth, stable entry into a partbeing machined, thereby allowing stable operation for forming closedrill tolerance holes of the desired configuration. Referring now toFIG. 1, an adjustable indexable drill 10 may comprise a drill body 12,an inboard cartridge 14, and an outboard cartridge 16. Variousstructures, such as cap head screws for securing the cartridges 14 and16, and inserts described hereafter, are not shown in FIG. 1.

The drill body 12 may have an approximately cylindrical shape, and maycomprise one or more longitudinal gullets 18, each gullet 18 having aleading surface 20 and a trailing surface 22. The leading surface 20 andtrailing surface 22 may be about 90 degrees apart. Alternately, theleading surface 20 and trailing surface 22 may be more or less than 90degrees apart. An end of the drill body 12 may comprise a first facesurface 26 and a second face surface 28. The longitudinal gullets 18 mayextend from the face surfaces 26, 28 along at least a portion of thedrill body 12. One or more insert cartridges may be used with the drillbody, such as insert cartridges 14, 16, which may be affixed to thedrill body 12 adjacent the face surfaces 26, 28.

The drill 10 may use multiple cutting inserts 30 for reducing chip size.The inserts may be positioned such that the cutting paths of the insertsoverlap. As the drill diameter increases beyond the ability of thecutting paths to overlap each other correctly, additional inserts may beused. At least one cutting insert 30 may be affixed to each insertcartridge 14, 16. FIGS. 1 through 5 show adjustable indexable drill 10utilizing four or more cutting inserts 30, 31, 32, 33 for illustrativepurposes. It may be possible for some applications to use fewer thanfour inserts. In an aspect of the invention, the drill has the abilityto be adjusted within a size range. The adjustability as an example asprovided by allowing outboard cartridge 16 to be movable, and positionedopposite a fixed insert cartridge 14 at substantially 180°. Theadjustability of the movable cartridge allows adjustment of the drillingsize for accurate adjustment of the drill to a particular hole sizerequirement. The adjustability also allows for compensation of wornmachine spindles, worn tool holders or poor setup conditions. Theability to drill a finished hole in a single operation eliminatesadditional boring and reaming operations, while achieving the desiredfinish hole size. This in turn reduces the drilling and boring inventorywhich is necessary for a particular application, as the drill size rangeeliminates the need for additional boring or reaming tools as well asreduces the need for specially built drill sizes. This also eliminatesthe lead time and expense of such custom-made items. As the desired holediameter increases, additional inserts may be used, such as for examplebut not limited to six inserts or eight inserts. Conversely, as thedesired hole diameter decreases, fewer inserts may be used, such as forexample but not limited to two or three inserts. The cutting inserts 30,31, 32, 33 comprise cutting geometry that may include cutting edges 40,41, 42, 43, with an apex 44 formed thereon. The apex in the exampleshown is provided by cutting edges extending at an angle therefrom, suchas about 20 degrees. The inserts may be indexable for providing one ormore additional cutting edges 40′, 41′, 42′, 43′.

The inboard cartridge 14 may comprise a cutting face comprising aninsert pocket positioned adjacent the axis of the drill body. Thecutting insert 30 may be affixed in the insert pocket on the inboardcartridge 14 such that the cutting edge 40 is capable of cutting thecentermost portion of the hole diameter.

The outboard cartridge 16 may comprise a cutting face comprising aninsert pocket positioned adjacent the edge of the drill body. Thecutting insert positioned for cutting the outermost portion of the holediameter may be affixed to the insert pocket on the outboard cartridge16. The cutting face on the outboard cartridge 16 may be about 180degrees from the cutting face on the inboard cartridge.

The first and second face surfaces 26, 28 may be angled surfaces. Asshown in FIGS. 2 and 3, the face surfaces 26, 28 may be angled at anangle A away from a perpendicular plane by a predetermined amount, suchas about 2 to 5 degrees. Alternately, the face surfaces 26, 28 may beangled away from a perpendicular plane by about ½ to 10 degrees orgreater. One or both face surfaces 26, 28 may be angled such that anormal vector of the face surface remains parallel to the gullet leadingsurface 20. Alternately, the face surfaces may have an obliqueorientation. The sloping of surfaces 26 and 28 provides for smooth entryinto a part surface, and facilitates stabilization of the drill duringuse. This also provides the function of allowing the center insert,which in this example is insert 30, and particularly the apex 44thereof, to begin forming a track in the cutting path as the opposite ornext inboard insert enters the part. The configuration allows the drillto begin to track at this point before the outer inserts begin to cut,thereby providing smooth and stable entry into the part. Angling theface surfaces 26, 28 away from the perpendicular plane positions theaffixed insert cartridges 14, 16 on a corresponding angle, therebyresulting in the cutting edges 40, 41, 42, 43 to be positioned such thatthe inner cutting edge 40 extends outwardly to the greatest extent, withsubsequent inserts being positioned away from the front of the drill.This positioning of inserts 30, 31, 32 and 33 allows each successiveinsert to effectively begin forming a cut, or track, before the nextinsert begins to cut, and so forth until each insert is engaging thepart. The center insert 30 therefore begins a slight tangential loadingbefore insert 31 begins cutting, and similarly in turn for inserts 32and 33. The smooth entry into the part avoids wobble which may causecatastrophic rebounding in drilling with one insert effective drillingsystems.

The first and second face surfaces 26, 28 may comprise a drive featureadjacent the aperture, or hole 48, extending toward an edge of the drillbody, such as for example but not limited to one or more longitudinalserrations or longitudinal keyways or other geometry capable ofrestraining the cartridges 14, 16 when installed on the face surfaces26, 28. As shown in FIGS. 4A and 4B, the first and second face surfaces26, 28 may comprise a drive feature, such as serrations 50 over at leasta portion of the face surfaces. As shown in this example, the serrationsare 60 degree serrations, but other angle serrations may be suitable asdesired. Alternatively, a drive key type of arrangement could be used orany other suitable drive configuration. The inboard cartridge 14 and theoutboard cartridge 16 may have corresponding geometry for engaging therestraining geometry on the face surfaces 26, 28, such as correspondingserrations, drive keyways or other geometry capable of restraining thecartridges 14, 16 when installed on the face surfaces 26, 28 as seen inFIGS. 4C and 4D. The drill body 12 may have apertures extending into thedrill body, or holes 48, for receiving screws or fasteners, such as caphead screws (not shown) for affixing the cartridges 14, 16. Thecartridges 14, 16 may be releasably affixed to the drill body 12 byfasteners such as for example but not limited to screws or otherfasteners. The fasteners may be socket head cap screws. This designallows the cartridges 14 and 16 to be selectively replaced, to alloweffective replacement of the front cutting surfaces associated with thedrill assembly, in a simple and effective manner. The design of thepresent invention also allows the distance from the drill bodytransition to the cutting insert pockets 34 to be kept short, to reduceany bending moments on the inserts. The distance from the end of thedrill body 12 to the cutting edge 40 may be in a range of about ½ to 1inch (about 12 to 25 millimeters). Alternately, the distance from theend of the drill body 12 to the cutting edge 40 may be in a range ofabout ¾ to 2 inch (about 19 to 51 millimeters). Supporting thecartridges close to the cutting edge tends to reduce forces in the drill10.

The inboard cartridge 14 and the outboard cartridge 16 may haveapertures through the cartridges for affixing the cartridges to thedrill body. As shown in FIGS. 4B and 5, an aperture 52 through theinboard cartridge 14 and aperture 54 through the outboard cartridge 16may comprise a counter-bore to provide clearance for a screw head orother fastener feature. For example, cap head screws (not shown) may beused to fasten the cartridges 14 and 16 via apertures 52 and 54, and inassociation with apertures formed on the face sides 26 an 28. Theposition of mounting apertures 48, 52, 54 may allow a user to installthe cartridges from the face end of the drill. By positioning themounting apertures 48, 52, 54 toward the face end of the drill, a usermay be able to remove the cartridges while the drill is positioned in amachine spindle, which may save time for the user.

Alternately, one or more of the cartridges may be integrated into thedrill body (not shown).

The gullet 18 may have a shape that opens the gullet to allow lessimpedance to the chip flow. The leading surface 20 of the gullet may beapproximately flat. The trailing surface 22 may be an elliptical concavesurface as shown in FIG. 1. The elliptical trailing surface 22 mayreduce the amount of coolant pressure and flow required to evacuate thechip rearward and away from the cut. Reducing coolant pressure andvolume may reduce the amount of misting of the coolant to be containedby filtration or other processes. For some materials, the indexabledrill 10 may enable dry cutting.

The cutting inserts 30, 31, 32, 33 may be positioned in pockets orcavities cut into the inboard and outboard cartridges 14, 16. Thepockets may be shaped to correspond to at least a portion of the shapeof the inserts. Further, the pockets may be shaped such that the insertsare angled with respect to a surface of the cartridges. The rotation ofthe insert pocket outward of the 20 degree apex may reduce “push off” ofthe center insert caused by the lower linear velocity of the insert nearthe centerline of the hole, such as by 1.5 to 2.75 degrees fromperpendicular for example. Other amounts of rotation are contemplated asmay be desired for various applications.

The drill 10 may be adjustable to different diameters within a sizerange. The outboard cartridge 16 may be a movable cartridge adjacent theface surface and selectively slidable along the directional feature. Asshown in FIGS. 4B and 5A, the aperture 54 may be a slot along thedirection of serrations 50. The slot may be sized to allow translationof the outboard cartridge 16 about 1/16 to ½ inch (about 1 to 12millimeter) or more for larger drill bodies 12. Alternately, the slotmay be sized to allow translation of the outboard cartridge 16 about ⅛to ¼ inch (about 2 to 6 millimeters). Other amounts of translation arecontemplated as may be desired for various applications. In operation,to adjust the outboard cartridge 16, the fastener affixing the cartridgeto the drill body may be loosened, allowing the cartridge to slide ortranslate the length of the slot. When the cartridge is positioned asdesired, the fastener may be re-tightened to affix the cartridge to thedrill body.

An adjustment to the drilling diameter may allow the end user to adjustthe drill to accommodate various hole diameters. Adjustability allowsfor the user to compensate for worn machine spindles, worn tool holders,or poor setup conditions. The drill adjustment may also reduce costlysecondary operations such as boring or reaming after drilling. Theadjustability feature may also reduce the amount of drilling and boringtool inventory maintained by a manufacturing facility. Further, theadjustability feature may also reduce the need for expensive specialorder drill sizes. As an example, a family of drill systems may beprovided in overlapping drill sizes, which for inserts as described inexamples herein, may be in the range of approximately 0.200 inches ondiameter to enable the hole drilling of a virtually infinite amount ofhole sizes. For smaller hole configurations, the adjustability providedby the tool according to the invention may be smaller, such as in therange of about 0.125 inches for example. In general, the degree ofadjustability may be of alternative ranges as may be desired, such as inthe range of 1/16 to ½ inch for example. The ability to provideadjustment according to the invention thereby allows desired finish holesizes to be produced.

The adjustable indexable drill 10 may use multiple inserts that maydistribute cutting forces over a cut width, with a slightly thickerinsert. The insert edge has a more free cutting rake or inclination thatis allowed by the stability of the drill. By eliminating honed edges andstrengthening the cutting area, less power may be used to drill thehole, providing a savings to the user. Smaller insert sizes may also useless material in the cutting tool insert. The one or more cuttinginserts may be fastened to the at least one cartridge, such ascartridges 14 and 16, in any suitable manner, such as by cap head screws(not shown) or the like.

Turning to FIG. 6, there is shown in FIGS. 6A-6D in more detail a trigontype of insert 60 that may be used in the drill according to theexamples of the invention. In FIG. 6, the trigon insert 60 includesthree sides 62 having first and second portions 64 and 66, with portion64 forming a cutting edge 68 and relief surfaces at about 7 and 15degrees respectively, as shown in the cross-sectional view. A centralaperture 69 for a fastening member is provided. As seen in FIG. 6B, thesides 62 may be angled at a desired angle relative to an adjacent side62, such as oriented at angles A of about 80 degrees plus/minus 0.5degrees, and each include two sections 70 and 72 angled at a desiredangle B, such as oriented at an exterior included angle of about 160degrees as shown in this example. The cutting edges 68 are provided oneach surface 62, extending from the axial center of the side 62. Thecutting edges 68 are substantially tangent to inscribed circle C fromdead center of insert 60. The diameter of circle C may be of a desireddimension D, such as 7.938 plus or minus 0.05 mm as an example. A radiusF may be provided between sides 62, such as a radius of 0.787 mm forexample. The cross section shown in FIG. 6C is taken along line 6C-6C ofFIG. 6B. As shown in this Fig., the aperture 69 has a desiredconfiguration for mating with a attachment screw, with an outboarddimension G, such as a dimension of 4.93 plus or minus 0.07 mm, and aninboard dimension H, such as a dimension of 3.23 plus or minus 0.07 mm.A radius I may be formed at a midpoint of aperture 69, such as a radiusof 2.362 for example. At the outboard side, the aperture 69 may have aportion 65 having a counterbore J of 0.51 plus or minus 0.07 mm forexample. A radius may be formed between portion 65 and the adjacentportion of the aperture 69, such as a radius of 0.203 for example. Thesurfaces 64 and 66 may be formed at desired angles to the cutting edge68, such as at a first primary clearance angle K for surface 64, such as7 degrees, and a secondary clearance angle L for surface 66, such as 15degrees. If desired, only a primary clearance surface may be used. Inthis example, the dimensions of the primary and secondary clearancesurfaces 64 and 66 may be selected as desired. The insert 60 may have adesired thickness N, such as 3.96 plus or minus 0.02 mm, with surface 64having a dimension O, such as 1.905 mm. In this and other examples, theinserts are designed to have a larger thickness dimension than ISOstandard thicknesses, to provide strength and durability. For example,the thickness is at least 0.4 mm greater than the international standardthickness. The enlarged partial section of FIG. 6D, taken at section 6Dof FIG. 6C, shows the detail of the cutting edge portion 68 and chipbreaker surface 63. The cutting edges 68 may include a plurality ofcutting components, which cooperate together to provide the desiredcutting surface for the material and/or drilling application. Ingeneral, the insert 60 is designed to cut when rotationally driven inconjunction with holder in a predetermined direction. The insertaperture 69 cooperates with an aperture in the inboard cartridge 14 orthe outboard cartridge 16 to secure insert 60 within a pocket on thecartridges 14 and 16 for example. The aperture 69 may be formed withcountersunk portions formed as a bearing surface adapted to be engagedby a corresponding tapered or like surface on a fastening member such asa screw or the like, and the aperture 69 and corresponding aperture in acartridge 14 or 16 may be offset, such that upon securing insert 60within a pocket, the insert 60 will be forced against seating surfacesin the pocket. Adjacent the cutting edges 68 of each side 62, thecutting lip or chip breaker surfaces 63 are formed as seen in FIG. 6D,to form desired chip forming and breaking surfaces in conjunction withthe cutting edge 68. Other aspects of a particular type of trigon insertare noted in these Figs, but it should also be understood that othertrigon or trochoid inserts may be formed differently so as to besuitable for use for various applications if desired. In this example,the particular trigon insert 60 has an isometric configuration and has apredetermined included angle which may vary in accordance with the sizeof the drilling tool if desired. The insert 60 also has primary andsecondary clearance surfaces, but it should also be understood thatother configurations are contemplated.

In FIGS. 7A-7D, a diamond shaped insert 80 is shown as an example of aninsert usable in the drilling system. The diamond shaped insert 80 isseen to have four sides with each having a cutting edge 81 associatedtherewith. In this example of a diamond shaped insert 80, as seen inFIG. 7B, the cutting edges 81 may be formed to be tangent to aninscribed circle 82, such as having a ⅜ inch diameter. The cutting edges81 are also formed at a predetermined angle 84 to one another, such asan angle of 80 degrees. As seen in FIG. 7C, showing a cross sectiontaken along line 7C-7C of FIG. 7B, a primary clearance surface 86 isformed behind the cutting edges 81, and the insert has a thickness 87,such as about 0.1563 mm. An enlarged detail of a cutting edge 81 isshown in FIG. 7D, showing a chip breaking surface 88 formed adjacent thecutting edge 81.

In FIGS. 8A-8D, a quadron shaped insert 90 is shown as an example of aninsert usable in the drilling system. The quadron shaped insert 90 isseen to have four sides with each having several cutting edges 91associated therewith. In this example, the quadroon insert 90 is formedto have a rhombus-type shape. As seen in FIG. 8B, the quadron insert 90may have a plurality of cutting edges formed to be tangent to aninscribed circle, such as having a diameter 92 of 0.3750 for example.The cutting edges 91 may be formed to be positioned at a desiredlocation relative to the centerline of each side of the quadron insert90, such as positioned at an angle 94, for example at an angle of 80degrees, to one another, such that the insert cutting edges 91 areskewed from the centerline of the insert 90 when positioned in acorresponding pocket 34 in a cartridge 14 or 16. Each side of thequadron insert 90 may be configured to have the cutting edges 91 formedat an included angle 96 to one another, such as at an angle of 160degrees for example. As shown in FIG. 8C, there may be provided aprimary clearance surface 100 adjacent each cutting edge 91, formed atan angle 102 such as an angle of 8 degrees for example. The attachmenthole 104 may be configured to allow attachment as desired. As seen inFIG. 8D, there may be a chip breaking surface 114 formed adjacent eachcutting edge 91.

In FIGS. 9A-9D, a square shaped insert 130 is shown as an example of aninsert usable in the drilling system. The square shaped insert 130 isseen to have four sides with each having a cutting edge 132 associatedtherewith. As seen in FIG. 9B, the cutting edges 132 may be formedtangent to an inscribed circle 134 having a predetermined diameter, suchas a ⅜ inch diameter for example. The cutting edges are formed at anangle 136, which for a square insert 130 is 90 degrees. The insert 130may have a side dimension 138, such as 0.3750 for example. As shown inFIG. 9C, there is a primary relief surface 140 formed at a predeterminedangle, such as an angle of 8 degrees, with details of the attachmenthole similar to the quadron insert mentioned previously for example. Asseen in FIG. 9D, there may be a chip breaking surface 144 formedadjacent each cutting edge 132.

The types of inserts shown in FIGS. 6-9 are examples of types which maybe suitably used, but other configurations are also contemplated, whileproviding indexability between the cartridges in which they arepositioned.

A further embodiment of the invention is shown in FIGS. 10A-10D, whereinthe adjustable drill may further include a centrally positioned drillinginsert that allows for increased stability during operation of thedrilling system, while still allowing indexability by means of theinsert configurations. In the embodiment as shown in FIG. 10A, the tool200 comprises one or more insert cartridges similar to priorembodiments, such as insert cartridges 204, 206, which may be affixed tothe drill body 202 adjacent the face surfaces 208, 210. Alternately, oneor more of the cartridges may be integrated into the drill body (notshown).

The drill 200 may use multiple cutting inserts 220. The inserts 220 maybe positioned such that the cutting paths of the inserts overlap as inprior embodiments, with more or less inserts usable depending on thedrill diameter. At least one cutting insert 220 may be affixed to eachinsert cartridge 204, 206. As in prior embodiments, FIGS. 10A-10D showan adjustable indexable drill 200 utilizing four or more cuttinginserts, but fewer or more than four inserts may be used. The drill 200has the ability to be adjusted within a size range, with theadjustability as in prior examples, provided by allowing outboardcartridge 206 to be movable, and positioned opposite a fixed insertcartridge 204 at substantially 180°. Instead of being fixed, thecartridge 204 could also be made to be movable. The adjustability of theat least one movable cartridge allows adjustment of the drilling sizefor accurate adjustment of the drill to a particular hole sizerequirement. The cutting inserts 220 comprise a desired cuttinggeometry, and may be indexable for providing one or more additionalcutting edges.

The inboard cartridge 204 and outboard cartridge 206 may comprise acutting face comprising an insert pocket positioned adjacent the axis ofthe drill body. The cutting inserts 220 may be affixed in the insertpockets such as in prior examples. The cutting face on the outboardcartridge 206 may be about 180 degrees from the cutting face on theinboard cartridge 204.

The first and second face surfaces 208 and 210 may be angled surfaces,such as described in prior examples. One or both face surfaces 208 and210 may be angled in alternative manners as in prior examples, such ashaving a normal vector of the face surface which remains parallel to thegullet leading surface, or alternately, the face surfaces may have anoblique orientation.

As in prior examples, the first and second face surfaces 208 and 210 maycomprise a drive feature to drive the cartridges 204 and 206, such asserrations 214 over at least a portion of the face surfaces, a drive keytype of arrangement or any other suitable drive configuration. Theinboard and outboard cartridges 204 and 206 may have cooperatingstructures or geometry for engaging the drive feature associated withthe face surfaces 208, 210, such as corresponding serrations, drivekeyways or other suitable structures or geometry. The drill body 202 mayhave apertures extending into the drill body, or holes 212, forreceiving screws or fasteners, such as cap head screws (not shown) foraffixing the cartridges 204 and 206. The cartridges 204 and 206 may bereleasably affixed to the drill body 202 by fasteners such as forexample but not limited to screws or other fasteners. The fasteners maybe socket head cap screws. This design allows the cartridges 204 and 206to be selectively replaced, to allow effective replacement of the frontcutting surfaces associated with the drill assembly for example. Thedesign similar to prior examples, allows the distance from the drillbody transition to the cutting insert pockets 34 to be kept short, toreduce any bending moments on the inserts.

The inboard cartridge 204 and the outboard cartridge 206 may haveapertures 216 and 218 respectively, through the cartridges for affixingthe cartridges to the drill body. As shown in FIGS. 10A and 10D, anaperture 216 through the inboard cartridge 204 provides for positioningthereof in a fixed position. The aperture 218 through the outboardcartridge 206 may be a movable cartridge adjacent the face surface andselectively slidable or movable relative to the tool axis. The aperture218 may be a slot to allow translation of the outboard cartridge 206 asin prior examples, with varying amounts of translation contemplated.Other aspects of the cartridges 204 and 206, the inserts 220 and holder202 may be similar to prior examples.

In this embodiment, there is also provided a central insert 230. Thecentral cutting insert 230 is positioned with first and second cuttingedges disposed adjacent the rotational axis of the drill. As an example,the central cutting insert is a blade type of insert or other suitableinsert configurations could be used. Alternatively, if desired, thecentral cutting edges could be integrally formed in the drill body. Thecentral insert 230 may facilitate a drilling operation by enhancingstability of the drilling tool, particularly as a hole gets deeper. Asthe outer cutting surfaces of the tool 200 are provided by cuttinginserts 220, which do not have a cutting margin, desired stabilitythroughout a drilling operation may be enhanced by providing a centralinsert 230. For example, at increasing hole depth, the provision of acentral insert 230 can provide additional stability to the tool duringdrilling. For example, at a hole depth of about one to four times depthto diameter or more, the stability provided by the central insert can behelpful. The centrally disposed cutting insert 230 can be of a varietyof types, such as a spade type of insert. In the example of FIG. 10, thecentral insert 230 may be an insert referred to as the Gen3sys insert assold by Allied Machine & Engineering Corp. Such an insert has a helicalmargin, curved cutting edges and a unique cutting geometry to providehigh penetration rates, durability hole quality, surface finish, trueposition and stability, and other advantages. In such an example, thedrilling tool provided with a centrally disposed cutting insert 230 ofthis or similar type would provide a highly stable system, whichincludes indexability of cartridges according to examples as set forthherein. The central insert 230 may be positioned in a slot 236 formed inthe holder or drill body 202, and may be secured in position by a setscrew (not shown) positioned in aperture 232 formed in the side of drillbody 202 adjacent the slot 236. The central insert 230 may include a cutout portion 234 forming a seating surface for the set screw for example.Other arrangements to secure the central insert 230 into the desiredposition are contemplated.

Turning to FIG. 11, an alternative tool 240 having similarcharacteristics to prior examples and having an alternative centralinsert 242 is shown. The central insert 242 in this example may besimilar to an ASC insert as sold by Allied Machine & Engineering Corp.In FIG. 12, an alternative tool 250 having similar characteristics toprior examples and having an alternative central insert 252 is shown.The central insert 252 in this example may be similar to a T-A insert assold by Allied Machine & Engineering Corp. Other insert typeconfigurations, such as provided by Allied Machine & Engineering Corp.may be used, or other centrally positioned cutting inserts orconfiguration may be usable and are contemplated in the invention.

Turning to FIGS. 13A-13D, in association with the examples provided orothers using a central cutting insert 260, the tool still providesadjustability in association with the cutting operation in a mannersimilar to prior examples. As seen in these Figs., the outboardcartridge 206 may be made adjustable, with the smallest drill diametershown in FIGS. 13A and 13B and the largest drill diameter shown in FIGS.13C and 13D. The FIGS. 13B and 13D shown the overlap of the variousinserts 220 on one side of the central insert 260 for clarity. Theinserts 220 may also be indexable to provide new cutting surfaces aspreviously described. As seen in FIG. 13D, even at the largest diameter,where the outboard cartridge 206 is fully extended, there is overlapbetween the central insert 260 and the adjacent cutting insert 220 inthe cartridge 206.

In association with the examples of the invention, there may also beprovided a modular drill body configuration as shown in FIGS. 14-18 forexample. In this example, the drill body or holder is shown at 300, andmay include a plurality of sections including a shank portion 302, atleast one extension portion 304 and a head portion 306, to allow adesired drill body to be configured. The modular system allows differentshank configurations 302 to be easily implemented, different lengths ofdrill body 300 to be easily implemented via the at least one extensionportion 304, and alternative head configurations 306 to be interchanged.In this example, a Cat 50 shank is shown, being a standard type of toolholder shank configuration used in drilling tools in association withdrill chucks. Other shank configurations can include, but are notlimited to Cat 40 tool holder shank configuration, BT tool holderconfigurations, floating tap tool holder configurations, straight shanktool holder configurations, R8 tool holder configurations, HSK toolholder configurations, Morse Taper tool holder configurations, Kaiserconfigurations, flanged straight configurations and others. In thisexample, the shank portion 302 is designed to mate with a particulardrive system, and has a connecting portion 310 associated therewith. Theconnecting portion can then mate with and connect an extension portion304 as shown, or be directly connected to a head portion 306 if desired.In this example, an extension portion 304 has a rearward mating portion312 and a forward mating portion 314. The rearward mating portion 312may have a reduced diameter which extends into the connecting portion310 of shank portion 302 (or another extension portion for example), andis selectively securable therewith. In this example, the mating portion312 may include a groove 316 positioned to correspond to apertures 318on the mating portion 310 of shank portion 302. Thrust screws (notshown) may be used in association with the apertures 318 to engage thegroove 316 and retain the extension portion 304 with shank portion 302,or other suitable arrangements may be used and are contemplated in theinvention. Alignment of the extension portion 304 with the shank portion302 may also be provided by alignment members 320 positioned inassociation with alignment seats 322 and 324 formed in the shank portion302 and extension portion 304 respectively, for example. Similarly, theforward mating portion 314 may be a recess to receive a connectingportion 328 of the head portion 306 in a similar manner, with apertures326 corresponding to a groove 330 formed in connecting portion 328 toretain head portion 306 therewith via thrust screws or the like.Alignment members 320 in association with seats 332 and 334 formed inthe extension portion 304 and head portion respectively, to facilitateconnecting the head portion 306 in a desired orientation. Otherconnection or alignment arrangements are usable and contemplated by theinvention.

As should be recognized, the modular arrangement of the tool holder ordrill body allows a great amount of flexibility in configuring the toolholder in various manners for various applications or environments.

In an alternative embodiment, the connection between a head portion 306and an extension portion 304 or shank portion 302 is shown in FIGS. 17and 18. In this example, the connecting portion 310 of the shank portion(or extension portion) may include a recess 348 into which a postextension 350 of the head portion 306 (or extension portion) ispositioned. An aperture 340 in the portion 310 is aligned with anaperture 352 formed in post 350, and a receiving screw 342 and thrustscrew 344 may be used to secure the post 350 in position. An alignmentor orientation pin 354 may cooperate with aperture 346 on the shankportion 302 and corresponding aperture (not shown) on the head portion306 to align these members. Other connection or alignment arrangementsare usable and contemplated by the invention.

It should be recognized that various modular configurations are easilyachieved. As shown in FIG. 19, the number of extension portions 304 canbe selected for a desired hole depth for example. Other variations, suchas changing the shank portion 302 and/or changing head portion 306 ifdesired.

To provide an idea of different shank configurations usable with theholder or drill body in different examples of the invention, FIGS. 20-22show various configurations that are usable. In FIG. 20, a Cat 50configuration is shown in a one piece or non-modular configuration forexample. In FIG. 21, a flanged straight shank portion is shown, and inFIG. 22, a Kaiser shank is shown. These configurations and others asnoted could be used in modular or non-modular configurations. Theaddition of the adjustable cutting head arrangement then providessignificant advantages as set forth in the examples of the invention.

While the invention has been illustrated and described in detail in theforegoing drawings and description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly illustrative embodiments thereof have been shown and described, andthat all changes and modifications that come within the spirit of theinvention described by the following claims are desired to be protected.Additional features of the invention will become apparent to thoseskilled in the art upon consideration of the description. Modificationsmay be made without departing from the spirit and scope of theinvention.

What is claimed is:
 1. An adjustable drill comprising: a drill bodyhaving a rotational axis, the drill body having at least one top facesurface comprising a drive feature and wherein the top face surface isangled obliquely away from a plane perpendicular to the rotational axisof the drill; and having at least one releasably affixed cartridgeadjacent the top face surface to be movable relative to the top facesurface, and cooperating with the drive feature to be driven therewith;at least one drilling insert releasably affixed to the at least onecartridge.
 2. The adjustable drill according to claim 1, furthercomprising a centrally disposed drilling system.
 3. The adjustable drillaccording to claim 2, wherein the centrally disposed drilling systemincludes a replaceable holder body in which at least one replaceablecutting insert is positioned.
 4. The adjustable drill according to claim2, wherein the centrally disposed drilling system is a modular systemwherein different drilling systems are accepted by a positioningconfiguration.
 5. The adjustable drill according to claim 1, wherein thedrill body has a plurality of sections including a shank section, atleast one extension section to extend the length of the drill body, anda head section.
 6. The adjustable drill according to claim 5, whereinthe modular drill body allows different shank configurations to bereplaced on the drill body, or different lengths of drill body to beformed via the at least one extension section, and alternative headconfigurations to be interchanged.
 7. The adjustable drill according toclaim 5, wherein the at least one extension section has two matingportions.
 8. The adjustable drill according to claim 7, wherein themating portions have dimensions to extend into or receive a connectingportion of shank section or another extension section or head section.9. The adjustable drill according to claim 7, wherein the matingportions include a groove positioned to correspond to apertures on amating portion of a shank section, other extension section or headsection.
 10. The adjustable drill according to claim 9, wherein thrustscrews are used in association with the apertures to engage the grooveand retain the at least one extension section with shank section, otherextension section or head section.
 11. The adjustable drill according toclaim 5, wherein alignment of the at least one extension section withthe shank section, other extension section or head section is providedby drive or key members provided in association with keyways thatprovide orientation of the components and drive the modular connectionbetween the components.
 12. The adjustable drill according to claim 5,wherein the connection between an extension section or head section andan extension section or shank section includes a post extension and areceiving aperture in which offset cone members engage.
 13. Theadjustable drill according to claim 12 wherein cone recesses areprovided in a center stud and draw in a cone on one end and invertedcone on other end which engage and lock into one another in thereceiving aperture.
 14. The adjustable drill according to claim 5,wherein the head section includes an alignment or orientation pin whichcooperates with an aperture on a shank section or extension section toalign these members.
 15. The adjustable drill according to claim 1,wherein the at least one cartridge comprises at least two insertpockets.
 16. The adjustable drill according to claim 1, wherein the atleast one insert is a trigon insert having three indexable sides withcutting edges, and first and second clearance surfaces adjacent thecutting edges of the insert.
 17. The adjustable drill according to claim1, wherein the central cutting system includes a replaceable holder bodyin which a replaceable cutting insert is positionable.
 18. Theadjustable drill according to claim 17, wherein the replaceable holderbody is positioned in a bore in the drill body, and is secured with thedrill body.
 19. The adjustable drill according to claim 17, wherein thecutting insert is a blade type of insert.
 20. An adjustable drillingsystem comprising, a holder body having two top face surfaces comprisinga drive feature; at least one cartridge positionable with each top facesurface with at least one of the cartridges being movable relative tothe top face surface, and cooperating with the drive feature to bedriven therewith; the at least one cartridge including a cutting facecomprising at least one insert pocket adjacent the top of the cartridgeand at least one insert releasably affixed in the insert pocket; and acentral cutting system including first and second cutting edges disposedadjacent the rotational axis of the drill comprising a replaceableholder body in which a replaceable cutting insert is positionable. 21.The adjustable drill according to claim 20, wherein the replaceableholder body is positioned in a bore in the drill body, and is securedwith the drill body.
 22. The adjustable drill according to claim 20,wherein the first and second cutting edges are provided in associationwith a central cutting system selected from the group consisting of acutting insert, a solid carbide cutting member or combination.